In upcoming commits, virSecurityManagerSetAllLabel() will perform
rollback in case of failure by calling
virSecurityManagerRestoreAllLabel(). But in order to do that, the
former needs to have @migrated argument so that it can be passed
to the latter.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
We mirror the labeling strategy that was used for its sibling
image
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
This will be used for recursing into externalDataStore
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
Rename the existing virSecurityDACRestoreImageLabelInt
to virSecurityDACRestoreImageLabelSingle, and extend the new
ImageLabelInt handle externalDataStore
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
This will simplify future patches and make the logic easier to follow
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
The only caller always passes in a non-null parent
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1755803
The /dev/tpmN file can be opened only once, as implemented in
drivers/char/tpm/tpm-dev.c:tpm_open() from the kernel's tree. Any
other attempt to open the file fails. And since we're opening the
file ourselves and passing the FD to qemu we will not succeed
opening the file again when locking it for seclabel remembering.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
While in most cases we want to remember/recall label for a
chardev, there are some special ones (like /dev/tpm0) where we
don't want to remember the seclabel nor recall it. See next
commit for rationale behind.
While the easiest way to implement this would be to just add new
argument to virSecurityDACSetChardevLabel() this one is also a
callback for virSecurityManagerSetChardevLabel() and thus has
more or less stable set of arguments. Therefore, the current
virSecurityDACSetChardevLabel() is renamed to
virSecurityDACSetChardevLabelHelper() and the original function
is set to call the new one.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
So far all items on the chown/setfilecon list have the same
.remember value. But this will change shortly. Therefore, don't
try to lock paths which we won't manipulate XATTRs for.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
If user has two domains, each have the same disk (configured for
RW) but each runs with different seclabel then we deny start of
the second domain because in order to do that we would need to
relabel the disk but that would cut the first domain off. Even if
we did not do that, qemu would fail to start because it would be
unable to lock the disk image for the second time. So far, this
behaviour is expected. But what is not expected is that we
increase the refcounter in XATTRs and leave it like that.
What happens is that when the second domain starts,
virSecuritySetRememberedLabel() is called, and since there are
XATTRs from the first domain it increments the refcounter and
returns it (refcounter == 2 at this point). Then callers
(virSecurityDACSetOwnership() and
virSecuritySELinuxSetFileconHelper()) realize that refcounter is
greater than 1 and desired seclabel doesn't match the one the
disk image already has and an error is produced. But the
refcounter is never decremented.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1740024
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
This effectively reverts d7420430ce and adds new code.
Here is the problem: Imagine a file X that is to be shared
between two domains as a disk. Let the first domain (vm1) have
seclabel remembering turned on and the other (vm2) has it turned
off. Assume that both domains will run under the same user, but
the original owner of X is different (i.e. trying to access X
without relabelling leads to EPERM).
Let's start vm1 first. This will cause X to be relabelled and to
gain new attributes:
trusted.libvirt.security.ref_dac="1"
trusted.libvirt.security.dac="$originalOwner"
When vm2 is started, X will again be relabelled, but since the
new label is the same as X already has (because of vm1) nothing
changes and vm1 and vm2 can access X just fine. Note that no
XATTR is changed (especially the refcounter keeps its value of 1)
because the vm2 domain has the feature turned off.
Now, vm1 is shut off and vm2 continues running. In seclabel
restore process we would get to X and since its refcounter is 1
we would restore the $originalOwner on it. But this is unsafe to
do because vm2 is still using X (remember the assumption that
$originalOwner and vm2's seclabel are distinct?).
The problem is that refcounter stored in XATTRs doesn't reflect
the actual times a resource is in use. Since I don't see any easy
way around it let's just not store original owner on shared
resources. Shared resource in world of domain disks is:
- whole backing chain but the top layer,
- read only disk (we don't require CDROM to be explicitly
marked as shareable),
- disk marked as shareable.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
One caller in particular (virSecurityDACSetImageLabelInternal)
will want to have the feature turned on only in some cases.
Introduce @remember member to _virSecurityDACChownItem to track
whether caller wants to do owner remembering or not.
The actual remembering is then enabled if both caller wanted it
and the feature is turned on in the config file.
Technically, we could skip over paths that don't have remember
enabled when creating a list of paths to lock. We won't touch
their XATTRs after all. Well, I rather play it safe and keep them
on the locking list for now.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Both DAC and SELinux drivers support transactions. Each item on
the transaction list consists of various variables and @restore
is one of them. Document it so that as the list of variables grow
it's easier to spot which variable does what.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
The way that virSecurityDACRecallLabel is currently written is
that if XATTRs are not supported for given path to the caller
this is not different than if the path is still in use. The value
of 1 is returned which makes secdrivers skip label restore.
This is clearly a bug as we are not restoring labels on say NFS
even though previously we were.
Strictly speaking, changes to virSecurityDACRememberLabel are not
needed, but they are done anyway so that getter and setter behave
in the same fashion.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
We're setting seclabels on unix sockets but never restoring them.
Surprisingly, we are doing so in SELinux driver.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
This reverts commit a5e1602090.
Getting rid of unistd.h from our headers will require more work than
just fixing the broken mingw build. Revert it until I have a more
complete proposal.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
util/virutil.h bogously included unistd.h. Drop it and replace it by
including it directly where needed.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The default permissions (0600 root:root) are of no use to the qemu
process so we need to change the owner to qemu iff running with
namespaces.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Security labeling of disks consists of labeling of the disk image
itself and it's backing chain. Modify
virSecurityManager[Set|Restore]ImageLabel to take a boolean flag that
will label the full chain rather than the top image itself.
This allows to delete/unify some parts of the code and will also
simplify callers in some cases.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Now that we have seclabel remembering we can safely restore
labels for shared and RO disks. In fact we need to do that to
keep seclabel refcount stored in XATTRs in sync with reality.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
This also requires the same DAC label to be used for shared
paths. If a path is already in use by a domain (or domains) then
and the domain we are starting now wants to access the path it
has to have the same DAC label. This might look too restrictive
as the new label can still guarantee access to already running
domains but in reality it is very unlikely and usually an admin
mistake.
This requirement also simplifies seclabel remembering, because we
can store only one seclabel and have a refcounter for how many
times the path is in use. If we were to allow different labels
and store them in some sort of array the algorithm to match
labels to domains would be needlessly complicated.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Because the implementation that will be used for label
remembering/recall is not atomic we have to give callers a chance
to enable or disable it. That is, enable it if and only if
metadata locking is enabled. Otherwise the feature MUST be turned
off.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
We are setting label on kernel, initrd, dtb and slic_table files.
But we never restored it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
It helps whe trying to match calls with virSecurityDACSetAllLabel
if the order in which devices are set/restored is the same in
both functions.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
When iterating over list of paths/disk sources to relabel it may
happen that the process fails at some point. In that case, for
the sake of keeping seclabel refcount (stored in XATTRs) in sync
with reality we have to perform rollback. However, if that fails
too the only thing we can do is warn user.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
It's important to keep XATTRs untouched (well, in the same state
they were in when entering the function). Otherwise our
refcounting would be messed up.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Just like for SPICE, we need to change the permissions on the DRI device
used as the @rendernode for egl-headless graphics type.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Trying to use virlockd to lock metadata turns out to be too big
gun. Since we will always spawn a separate process for relabeling
we are safe to use thread unsafe POSIX locks and take out
virtlockd completely out of the picture.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
When metadata locking is enabled that means the security commit
processing will be run in a fork similar to how namespaces use fork()'s
for processing. This is done to ensure libvirt can properly and
synchronously modify the metadata to store the original owner data.
Since fork()'s (e.g. virFork) have been seen as a performance bottleneck
being able to disable them allows the admin to choose whether the
performance 'hit' is worth the extra 'security' of being able to
remember the original owner of a lock.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
We switched to opening mode='bind' sockets ourselves:
commit 30fb2276d8
qemu: support passing pre-opened UNIX socket listen FD
in v4.5.0-rc1~251
Then fixed qemuBuildChrChardevStr to change libvirtd's label
while creating the socket:
commit b0c6300fc4
qemu: ensure FDs passed to QEMU for chardevs have correct SELinux labels
v4.5.0-rc1~52
Also add labeling of these sockets to the DAC driver.
Instead of duplicating the logic which decides whether libvirt should
pre-create the socket, assume an existing path meaning that it was created
by libvirt.
https://bugzilla.redhat.com/show_bug.cgi?id=1633389
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
It may happen that in the list of paths/disk sources to relabel
there is a disk source. If that is the case, the path is NULL. In
that case, we shouldn't try to lock the path. It's likely a
network disk anyway and therefore there is nothing to lock.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
This shouldn't be needed per-se. Security manager shouldn't
disappear during transactions - it's immutable. However, it
doesn't hurt to grab a reference either - transaction code uses
it after all.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Lock all the paths we want to relabel to mutually exclude other
libvirt daemons.
The only hitch here is that directories can't be locked.
Therefore, when relabeling a directory do not lock it (this
happens only when setting up some domain private paths anyway,
e.g. huge pages directory).
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Firstly, the message that says we're setting uid:gid shouldn't be
called from virSecurityDACSetOwnershipInternal() because
virSecurityDACRestoreFileLabelInternal() is calling it too.
Secondly, there are places between us reporting label restore and
us actually doing it where we can quit. Don't say we're doing
something until we are actually about to do it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
So far the whole transaction handling is done
virSecurityDACSetOwnershipInternal(). This needs to change for
the sake of security label remembering and locking. Otherwise we
would be locking a path when only appending it to transaction
list and not when actually relabeling it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
It will be desirable to run transactions more often than we
currently do. Even if the domain we're relabeling the paths for
does not run in a namespace. If that's the case, there is no need
to fork() as we are already running in the right namespace. To
differentiate whether transaction code should fork() or not the
@pid argument now accepts -1 (which means do not fork).
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
These two functions (virSecurityDACSetOwnership and
virSecurityDACRestoreFileLabelInternal) do not really change
@src. Make it const.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
This function is going call security manager APIs and therefore
it needs pointer to it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
This function is going call security manager APIs and therefore
it needs pointer to it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Extend the DAC and SELinux modules with support for the tpm-emulator.
We label the Unix socket that QEMU connects to after starting swtmp
with DAC and SELinux labels. We do not have to restore the labels in
this case since the tpm-emulator will remove the Unix socket when it
terminates.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
This patch adds support for an external swtpm TPM emulator. The XML for
this type of TPM looks as follows:
<tpm model='tpm-tis'>
<backend type='emulator'/>
</tpm>
The XML will currently only define a TPM 1.2.
Extend the documentation.
Add a test case testing the XML parser and formatter.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
We're freeing individual items in it but not the array itself.
==19200== 40 bytes in 1 blocks are definitely lost in loss record 847 of 1,059
==19200== at 0x4C2D12F: realloc (vg_replace_malloc.c:785)
==19200== by 0x52C5532: virReallocN (viralloc.c:245)
==19200== by 0x52C5628: virExpandN (viralloc.c:294)
==19200== by 0x52C58FC: virInsertElementsN (viralloc.c:436)
==19200== by 0x542856B: virSecurityDACChownListAppend (security_dac.c:115)
==19200== by 0x54286B4: virSecurityDACTransactionAppend (security_dac.c:167)
==19200== by 0x542902F: virSecurityDACSetOwnershipInternal (security_dac.c:560)
==19200== by 0x54295D6: virSecurityDACSetOwnership (security_dac.c:650)
==19200== by 0x542AEE0: virSecurityDACSetInputLabel (security_dac.c:1472)
==19200== by 0x542B61D: virSecurityDACSetAllLabel (security_dac.c:1693)
==19200== by 0x542DD67: virSecurityManagerSetAllLabel (security_manager.c:869)
==19200== by 0x54279C2: virSecurityStackSetAllLabel (security_stack.c:361)
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
virSecurityManagerDomainSetPathLabel is used to make a path known
to the security modules, but today is used interchangably for
- paths to files/dirs to be accessed directly
- paths to a dir, but the access will actually be to files therein
Depending on the security module it is important to know which of
these types it will be.
The argument allowSubtree augments the call to the implementations of
DomainSetPathLabel that can - per security module - decide if extra
actions shall be taken.
For now dac/selinux handle this as before, but apparmor will make
use of it to add a wildcard to the path that was passed.
Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
SELinux and DAC drivers already have both functions but they were not
exported as public API of security manager.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Until now we ignored user-provided backing chains and while detecting
the code inherited labels of the parent device. With user provided
chains we should keep this functionality, so label of the parent image
in the backing chain will be applied if an image-specific label is not
present.
Add helpers that will simplify checking if a backing file is valid or
whether it has backing store. The helper virStorageSourceIsBacking
returns true if the given virStorageSource is a valid backing store
member. virStorageSourceHasBacking returns true if the virStorageSource
has a backing store child.
Adding these functions creates a central points for further refactors.
For a logged in user this a path like /dev/dri/renderD128 will have
default ownership root:video which won't work for the qemu:qemu user,
so we need to chown it.
We only do this when mount namespaces are enabled in the qemu driver,
so the chown'ing doesn't interfere with other users of the shared
render node path
https://bugzilla.redhat.com/show_bug.cgi?id=1460804
